You need to kill someone. This can be done by any means, but be warned that some characters take this harder than others and can drive them to depression. Killing defenseless people takes more of a toll than killing hostiles.
The easiest people to kill are the old couple at the quiet house. Neither puts up a fight, and you can easily beat granny and grandpa to death for 80G, though you should only kill one as not to make your character spiral into a depression.
Note: As Gothic Nurse stated, and as tested on an alt getting hit DOES count. So you can either kill someone or get hurt. Pick your poison for this one.